The invention provides a real-time monitoring device for a field bus link based on ARM (Advanced RISC Machines), comprising an ARM processor, an FPGA ((Field Programmable Gate Array) module, a field bus communication interface and a man-machine interaction interface, wherein data on the field bus link are downloaded in the FPGA module through the field bus communication interface; the ARM processor reads the data in the FPGA module and obtains state and alarming information on the field bus link and the state and the alarming information of equipment linked on the field bus link; the man-machine interface interaction interface displays the data; the generated alarming information is input to the FPGA module and uploaded to the field bus link; the input information is input to the ARM processor through the man-machine interface; and the input information is written in the FPGA model in real-time and transmitted to the field bus link through the field bus communication interface. The device provided by the invention can be flexibly applied to real-time monitoring at workshop or equipment level and solving the problem of real-time monitoring at the workshop or equipment level.